Fuse plug and socket



NOV. 7, 1950 Q, CAMPBELL 2,528,857

FUSE PLUG AND SOCKET Filed Nov. 23, 1948 /8 If g 1 .E E ';l 22

III II m m /4 2a 20 T g 5 /5 2a [NYE/V709 R0. Out 8r Cam r 4 Y P BYQMW/ Patented Nov. 7, 19 0 UNITED? STATES PATENT OFFICE I 2,52s,s57-" 1 grusn rLUo ANnjsooK r RoyOliver Campbell, ,Maitla'nd, Ontario, Canada application November 23, 194s, Serial'No. 61,543 I This invention relates .to' fuse plugs'and. to sockets designed to cooperate with said plugs.

Since it is customary for inexperienced people to use tin foil and the like in a fuse socket, to reestablish the circuit after the fuse is blown, it is the primary object of the present invention to design and construct a fuse and a socket so con- 1 claim {(01. 200-119) i -11 The fuse socket or adaptercomprises an instructed that tin foil or the like may not be used to complete the circuit when the fuse is blown.

Serious fires have been caused by that practice because the tin foil used to reestablish the circuit is generally of greater current supporting capacity and will not afford the protection of the fuse. In that event when the line is overloaded the fuse no longer being a protection, trouble and fire may happen anywhere along the line, and since electrical wires are always mounted between walls and the ceiling serious trouble could be caused before it was noticed.

Another important object of the invention is teriorly threaded socket I5 secured to a nonconductive base H.

The'base is formed with an aperture I6 extending part way therethrough while a further aperture I! of substantially smaller diameter extends through the balance of the base and is disposed centrally of the larger hole I6. The smaller aperture [1 is threaded. A strip I8 of conductive material is used to join several sockets mounted in a fuse box.

A contactor is threadably engaged in aperture I! of the base I4. The contactor consists of a threaded shank I9 which fits the threaded hole 11, the said shank being formed with opposed projections so as to prevent the withdrawal therefore to provide means which will prevent the user from replacing a blown fuse by tin foil, pennies, etc.

Still another important object of .the invention is the provision of a sharp circular edge projecting from the fuse which will cut through soft pliable material which might be temporarily used to replace a blown fuse.

Still another important object is the provision of means whereby the circuit is opened when the fuse is removed from the socket and no electrical shock can be suffered by anyone attempting to remove or replace a blown fuse.

With these and other objects in view that may appear while the description proceeds the invention consists in the novel arrangement of parts as hereinafter more specifically set forth, claimed and shown in the accompanying drawing forming part of this application and in which:

Fig. 1 is a side elevational view of the invention partly shown in cross section;

Fig. 2 is a detail of the fuse per se;

Fig. 3 is a detail of the fuse socket, and

Fig. 4 is an underneath plan view of the fuse.

Referring more in detail to the drawing in which similar reference characters designate corresponding parts throughout the several views it will be seen the invention comprises a fuse I0,

the top portion of which is of conventional contherefrom. A large disc 2I is formed above the shank I9 and acts as a stop for projection 12 of the fuse. Immediately above the'disc 2| is a further shank formed with a plurality of flutes 22 adapted to engage the flutes I4 of the projection I2.

The operation is as follows:

The fuse I0 is threaded in I5. When being threaded the projection I2 engages the flutes 22 and rotates the contactor. Since the shank I9 of the contactor is threaded it will move longitudinally of the hole I! until its extremity 23 comes in contact with member I8. This of course will complete the circuit and the fuse will be in oper- V ation. r 'Whenthe fuse becomes burned and is unscrewed from its socket I5 the contactor I9 is raised breaking its connection with the conductor strip I8. With the fuse removed it is impossible to complete the circuit even though a piece of tin foil or other conductive material is inserted in the socket I5. The circuit can only be reestablished by insertingv a new fuse of my improved type. If a piece of tin foil is inserted in the socket in an attempt to complete the circuit it will not interfere with the insertion of a new fuse as the cutting edge I3 of the projection I2 will cut through the tin foil so that the projection I2 can engage the fluted portion 22 to turn the contactor I9.

It is believed that the construction and advantages of the device may be apparent from the foregoing paragraphs taken in conjunction with the accompanying drawings without further detailed description.

While the preferred embodiment of the invention has been disclosed it is understood that minor changes in the details of construction, combination and arrangement of cooperating parts may I claim:

A fuse plug and socket comprising a non-conductive socket member having a screw-threaded bore extending through the bottom thereof, said bore having an enlarged upper end, a contact rod threaded in said bore adapted to move axially of said socket upon rotation, a disk on said rod be resorted to within the scope of what is claimed without departing from the spirit of the invention.

adapted to seat in the enlarged upper end of said bore to limit the axial movement of said rod, an

exteriorly fluted head above said disk of larger diameter than said rod, a contact member below; said contact rod adapted to be engaged by said,

contact rod upon downward movement thereof, a

' threaded contact shell surrounding the upper end? 4 projecting from its center contact, said extension being interiorly flutedf or interfitting engagement with the fluted head of said contact rod whereby said rod is rotated upon turning of said plug, said tubular extension having the interior of its lower end beveled to provide a cutting edge.

V ROY OLIVER CAMPBELL.

" REFERENCESCITED The following references are of record in the file'of this patent:

"YUNITED STATES PATENTS Number Name Date 1,70 ,150, Floring Mar. 19, 1929 1,863,383 Schmidt, Jr June 14, 1932 1,948,421 Johnson et a1 Feb. 20, 1934 1,952,151 Wadsworth Mar. 27, 1934 McEntee Apr. 26, 193 8 

